Topological transitions in spin interferometers

TL;DR

This paper demonstrates that topological transitions in spin transport can be controlled via spin-guiding fields, affecting quantum interference patterns and providing a method to measure spin-orbit interactions.

Contribution

It introduces a novel approach to induce and observe topological transitions in spin interferometers through manipulation of spin textures and Berry phases.

Findings

Topological transitions cause dislocations in conductance interference patterns.

Transitions are governed by the topology of spin textures, independent of nonadiabatic dynamics.

The phenomenon remains robust in the presence of disorder.

Abstract

We show that topological transitions in electronic spin transport are feasible by a controlled manipulation of spin-guiding fields. The transitions are determined by the topology of the fields texture through an effective Berry phase (related to the winding parity of spin modes around poles in the Bloch sphere), irrespective of the actual complexity of the nonadiabatic spin dynamics. This manifests as a distinct dislocation of the interference pattern in the quantum conductance of mesoscopic loops. The phenomenon is robust against disorder, and can be experimentally exploited to determine the magnitude of inner spin-orbit fields.